\left \{ {{x \leq1} \atop {\frac{1}{3}x \geq -3}} \right.<=> \left \{ {{x \leq1} \atop {x \geq -9}} \right.\\\ \\\ [-9; 1] " alt=" \left \{ {{1-x \geq 0} \atop {\frac{1}{3}x+3 \geq 0}} \right. <=> \left \{ {{x \leq1} \atop {\frac{1}{3}x \geq -3}} \right.<=> \left \{ {{x \leq1} \atop {x \geq -9}} \right.\\\ \\\ [-9; 1] " align="absmiddle" class="latex-formula">